Electric switches



Nov. 21, 1961 A. CLAREY ELECTRIC SWITCHES Filed Nov. 24, 1958 INVENTOR. Ale xdnder Cla'rey Q 3 E: H l 'l I r k 1.

ATTORNEY 3,tl1t),004 ELECTRIC S'WlTCI-ES Alexander (Zlarey, 610 W. 145th St., New York, NY. Filed Nov. 24, 1958, Ser. No. 775,915 4 flaunts. (Cl. 209-152) This invention relates to electric switches, and more particularly to a mercury switch, relay or the like.

In the manufacture of prior art mercury switches or relays for making or breaking electric circuits, two types are known, namely, (i) a mercury switch utilizing a tiltable tube partially filled with mercury, and (2) a mercury relay utilizing an electrically conductive plunger in one position of which, for closing the electric circuit, it is dipped into a receptacle partially filled with mercury. In both cases, a permanently fixed mounting is required. Moreover, such switches and relays are extremely sensitive to shocks and vibrations. For these and other reasons, they cannot be used with or on a piece of apparatus that may assume different positions; for instance, they cannot be used on ships, airplanes, submarines, and so forth. With such a type of switch or relay, permanent fixed mounting is required so that tilting of the same cannot take place unless intentionally actuated. Manner and place of mounting is therefore critical, so that universal use and freedom of location is not possible.

The present invention contemplates a mercury switch or relay that will be non-critical as to mounting.

The fundamental concept of the present invention is to provide a mercury switch or relay which will be equally operative in any position and on any apparatus whether fixed or movable, and will withstand shocks and vibration.

Also in its broad aspect, the invention provides a mercury switch or relay which functions to make and break an electric circuit independent of gravitation of the mercury.

Specifically, the invention provides a dip rod or plunger insertable into a confined body of mercury for making electric contact, and retractable therefrom for breaking electrical contact.

A further specific object of the invention is to provide means for maintaining the mercury chamber always completely filled with mercury irrespective of the position of the dip rod or plunger.

A still further object of the invention is to provide accommodation for mercury displaced by insertion of the plunger thereinto.

Other objects, advantages and novel structural features will become apparent to persons skilled in the art to which the invention appertains as the description proceeds, both by direct reference thereto and by implication from the context.

Referring to the accompanying drawing, in which like numerals of reference indicate the same or similar parts throughout the several views:

FIGURE 1 is a longitudinal sectional view of an electric switch in its off position, that is, in position by which the electric circuit is interrupted;

FIGURE 2 is a similar longitudinal sectional view of the same switch in its on position, that is, in position by which the electric circuit therethrough is completed;

FIGURE 3 is a longitudinal sectional view of a modified exemplification of the invention and showing the switch thereof in off position; and

FIGURE 4 is a cross sectional view taken on line IV'IV of FIG. 1.

In the specific embodiment of the invention illustrated in said drawings, and referring initially to FIGURES 1, 2 and 4, a cylindrical closed-bottom container 1 is provided which is preferably metallic so as tobe electrically 3,61%,W4 Patented Nov. 21, 1951 conductive. chamber which is filled from bottom to top thereof with a body of mercury 2. A screwed-in top 3 is shown for the mercury chamber, said top having a central opening providing a sliding fit for a coaxial dip rod or plunger comprised of an upper metallic section 4 and a lower insulative section 5. Said top 3 is also cylindrically hollow and internally screw-threaded proximate to its upper. extremity for receiving a plug 6 in threaded engagement therewith, the dip rod or plunger 4, 5 passing coaxially therethrough and protruding through the upper end thereof. Within the hollow of top 3 and beneath plug 6 is suitable packing 7, which may appropriately be laminated V-washers. Pressure induced by screwing plug 6 home will cause the packing to hug the dip-rod or plunger and, while permitting the plunger to slide, will provide a seal against escape of the mercury thereat. It will be ap preciated that the top 3, plug 6 and packing 7 constitute a stufiing box for the plunger.

Since the chamber in container 1 is filled from bottom to top with mercury, as shown in FIG. 1, with the plunger in its uppermost position, depression of the plunger into the chamber requires that accommodation be provided for mercury displaced thereby. This desideratum is accomplished by providing holes or escapement means 8 which may very appropriately be located in the side wall of the container 1 at about the middle of the length thereof. On the outside of the side wall of the container, tightly girdling the same, is a stretchable sleeve 9 of rubber or other suitable material. Displaced mercury forced from holes 8 will be trapped within said sleeve which stretches in the vicinity of said holes an amount suificient to accommodate the displaced mercury. When the plunger is retracted, both the suction produced thereby and the resilient pressure exerted by the resilient stretched sleeve will cause the extruded mercury to. return through holes 8 so the container chamberremains full of mercury for all positions of the plunger.

It has been indicated above that a lower plunger section 5 is insulative material, and it may now be pointed out that this section has a length such that its lower end never leaves the mercury chamber but may be raised proximate to the top thereof, and at the same time, the upper end of insulative section 5 is above. plug 6. This likewise means that the lower end of the conductive or metallic upper section 4 of the plunger is above, the plug and thus out of electrical contact either with the mercury or any metallic part of the container and stuffing box. While said plug may be an insulative material, the use of a metal plug will not result in short circuit when the section 5 of the plunger is in its completely raised position. However, to confine the breaking of the circuit to the departure of the conductive section 4 from the mercury, both said plug 6 and packing 7 are of insulative material. When the plunger is fully depressed, the in sulative section 5 is completely immersed in the mercury body, and the lower end portion of the conductive section 4 dips into the mercury. In this immersed position of the conductive section 4, the electric circuit, indicated by wire 11 to said section and wire 12 to the metallic mercury container, is completed. Conversely, upon withdrawal of the conductive section 4 from the mercury, the circuit is broken or in ofi condition.

In the showing of FIG. 3, I :form the chamber for the mercury 2 as a metallic bellows 10 which has an inherent resilient contraction. The bellows 10 will therefore provide displacement accommodation for mercury resulting from insertion of plunger 4, 5 into the body of mercury, and the contractive characteristic of the bellows will cause the mercury to follow the plunger as it retracts. In other respects, the above description will give an adequate understanding of the construction and opera- The interior of said container constitutes a tion of this modified showing. Sufiice it to say, that the bellows of FIG. 3, within container 1, replaces and performs the function of stretchable resilient sleeve 9 on the exterior of container 1 of the other figures, both said bellows and said sleeve constituting means for displace ment accommodation of the mercury when the plunger is depressed for the 011" position for the circuit.

While the plunger as herein shown may be directly operated by hand, in practice some suitable means will be utilized, such as actuation by a solenoid coil and spring loading, or by mechanical connections such as a lever arm thereto, a toggle or other expedients familiar to persons skilled in the art.

I claim:

1. An electric switch comprising a container with a bottom closure and a top having a stuffing box therein for effecting a top closure, a plunger slidable in said stuffing box for entry into and retraction substantially from the container as far as said top closure, a body of mercury filling said container from bottom to top closures thereof, escapement holes in the side of said container, and a stretchable sleeve at the outside of said container extending over said holes for accommodating mercury displaced by introduction of said plunger into said container and mercury.

2. An electric switch comprising a container with a bottom closure and a top having a stufling box therein for effecting a top closure, a plunger having an electrically conductive section at the end of the plunger more remote from the mercury and an insulative section at the other end of the plunger nearest to the mercury slidable in said stuffing box'for entry into and retraction substantially from the container as far as said top closure, a body of mercury filling said container from bottom to top closures thereof, said insulative section having a range of sliding at least as great as its own length for complete submersion in the'rnercury, said container having escapement holes in the side thereof for passage of mercury displaced by said plunger, and means for confining and returning that portion of the mercury to said container as the plunger retracts.

3'. An electric switch comprising a bellows-type container with a bottom closure and a top having a stuffing box therein for eifecting a top closure, a plunger slidable in said stuffing box for entry into and retraction substantially from within said bellows container as far as said top closure, 21 body of mercury filling said bellows container from bottom to top closures thereof, said plunger being insertable into said bellows container and said bellows container expanding in compensation for increased volu-me required by entry of said plungerthereinto, said bellows being inherently resilient for maintaining the bellows full as the plunger retracts.

4. An electric switch comprising a container providing a chamber filled with mercury, said chamber having a bottom closure and a top having a stuffing box thereat for effecting a top closure, a plunger projecting longitudinally through said stufling box, said plunger having a longitudinal electrically conductive section at the end of the plunger more remote from the mercury for exterior circuit connection and having a longitudinal insulative section at the other end of the plunger nearest to the marcury and directed inwardly of the chamber, said plunger being longitudinally slidable in said stufling box for entry into and retraction substantially from the container as far as said stuffing box top closure, said plunger and chamber having the respective longitudinal dimensions thereof extending in the same direction and said chamber having an internal longitudinal dimension greater than the longitudinal dimension of the insulative section of the plunger, the insulative section of the plunger thereby being immersible in its entirety in said chamber and mercury and always at least in part immersed therein, and said conductive section of the plunger being immersed in part in said chamber and mercury simultaneously with the complete immersion of said insulative section, and means excluding air from entry into said chamber and contact of air with said mercury and at the same time accommodating displacement of mercury by the introduction of said plunger thereinto.

References Cited in the file of this patent UNITED STATES PATENTS 1,983,150 Sigman Dec. 4, 1934 2,606,256 'Sissenwine et al. Aug. 5, 1952 2,720,562 McLaughlin Oct. 11, 1955 2,901,580 Kelly Aug. 25, 1959 

